Ore-screen.



R. P. AKINS.

ORE SCREEN.

APPLICATION FILED FEB.16, 1905.

Patented Mar. 15, 1910.

2 SHEETS-SHEET 1.

R. P. AKINS.

ORE SCREEN.

APPLICATION FILED PBB.16, 1905.

Patented Mar. 15, 1910.

ar cribs.

RANDALL P. AKINS, OF DENVER, COLORADO, ASSIGNOR TO THE COLORADO IRON WORKS COMPANY, OF DENVER, COLORADO.

ORE-SCREEN.

To all whom it may concern:

Be it known that I, RANDALL P. AKINs, a citizen of the United States, residing in the city and county of Denver and State of Colorado, have invented certain new and useful Improvements in Ore-Screens; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which itappertains to make and use the same, reference being had to the accompanying drawings, and to the figures of reference marked thereon, which form a part of this specification.

My invention relates to improvements in screens adapted for use in sizing or classifying ore preparatory to its treatment for the purpose of saving the precious metal values. It is evident that a screen of this character may be employed in any relation where it is important to properly perform, a screening, sizing or classifying function.

The screen is more especially intended for use where it is subjected to vibration as set forth in the application of Norman V. Fitts, filed Dec. 5th, 1904, Serial No. 235,465. However, as nothing is claimed in this application on the vibrating mechanism, only the screen itself and its spring support are illustrated.

The term screen as here employed, consists of a special construction of frame, to which the mesh material is applied.

The novel feature of this invention lies in the construction of the frame work, and the object sought to be attained by my improvement, is to cause the water after having "passed once through the mesh material, to

pass upwardly through the screen from beneath, and again act on the material to be screened. This same water may pass back and forth through the screen a number of times before it is discharged therefrom. This construction therefore obviates the necessity of delivering feed water to the top of the screen and effects an important degree of economy both in the amount of water used and in the mechanism employed.

Having set forth the function of my improved construction and the object to be attained thereby, I will proceed to describe the same in detail reference being made to the accompanying drawing in which is illustrated an embodiment thereof.

In this drawing, Figure 1 is a top or plan Specification of Letters Patent.

Application filed February 16, 1905.

Serial No. 245,956.

view of my improved screen with the mesh material removed. Fig. 2 is a section taken on the line 2-2 Fig. 1. Fig. 3 is a similar view with the several parts separated and ready to assemble. Fig. 4 is a sectional view showing the position 'of the screen when in use.

The same reference characters indicate the same parts in all the views.

Let the numeral 5 designate the rectangular outer frame work of the screen. Between the parallel sides 6 of this outer frame, are located bars 7 suitably spaced and connected with the ends 8 and 9 of the structure. These bars are cut out as shown at 10 to receive metal plates 12 which extend transversely across the screen between the sides 6, and curve upwardly at their lower extremities as shown at 13 to a point quite close to the sieve material 14, in order to cause the water which is passed through the screen and comes in contact with the plates 12, to pass upwardly through the sieve material as it flows downwardly in a suitably inclined plane which plane it must be assumed the screen occupies as shown in Fig. 4:. The plates 12 are shaped to correspond with the recesses or cut out portions 10 of the bars 7. At the lower extremity of each plate, is a narrow space A below the sieve through which the sand or other fine material which is passed through thescreen to engagement with the plates 12, escapes in order to prevent it from passing upwardly through the screen to the top thereof which is of course undesirable. A portion of the sand escapes at the extremity of each of the upper two plates and passes downwardly as indicated by the feathered arrows in Fig. 4C. The discharge of the balance of the material which passes through the screen, of course occurs at the lower extremity of the lowermost plate 12. My object is to discharge as large a portion of the water as possible up through the screen from each plate 12, but at the same time to prevent as far as possible the return of the fine material to the top of the screen, after the said material has once passed therethrough. In actual practice it is found that only a very small por tion of this material returns with the water to the top of the screen, the quantity being in fact so small as to amount to nothing comparatively. At the end of each plate 10 except the last or lowermost, lugs or pro- Patented Mar. 15, 19111.

water and material which passes through jections B are formed in the bars 7. In order to form a level surface for the sieve material 14, fillets or ribs 15 are applied to the plates 12 and in line with the bars 7. The fillets and bars are comparatively narrow, leaving the greater portion of the area of the plates 12 between the fillets, to receive the the screen. After the frame work is constructed, consisting of the outer frame, the parallel bars 7, the plates 12 and the fillets 15, the sieve material 1 1 is applied thereto in any suitable manner. At the head or upper extremity of the frame and lying in the plane of the sieve material, is a plate 16 upon which the material to be treated by the screen, is discharged in the first instance. This plate is connected with the frame work of the screen in any suitable manner.

By reference to Fig. 4: the manner of using the screen will be readily understood. It is provided with an inclosing housing and is connected by means of springs 18 and 19 with a frame work 20, the latter being mounted on a stationary structure 21. The means for vibrating the screen is not illustrated, as nothing is claimed thereon in this application. The material to be treated is fed to the screen from a chute 22 located at the upper extremity thereof; while the material rejected by the sieve, enters a conduit 23 at the lower extremity of the screen. The material which passes through the sieve, enters a rearwardly inclined chute 24 located at the lower extremity of and below the screen.

From the foregoing description the use and operation of my improved screen will be readily understood. Assuming that the device is suitably mounted as shown in Fig. 4, the pulp will be fed in the first instance to the plate 16. This pulp then passes to the upper portion of the sieve material 14. The water and the finer portion of the pulp will pass quickly through the upper part of the screen, leaving a space on the screen corresponding with that directly above the lower extremity of the first plate 1.2, practically free from water. Upon this space the material will have a tendency to stick and clog the screen. After the water passes through the screen, it comes in contact with the first plate 12, and as it passes downwardly, it is directed upwardly at the extremity of the plate by reason of the peculiar shape of the latter as heretofore ex plained. This upward current of water has sufficient momentum or impetus, to cause it to pass through the screen from beneath and act on the material which otherwise has a tendency to clog the screen on the transverse 1 portion directly above the lower extremity of the plate as above explained. The sand or fine material which is passed through the screen to the first plate 12, on the other hand passes over the lower extremity of the first plate below the screen, a portion of this fine material escaping from the screen at that point as indicated by the feathered arrow in Fig. 1, while the balance passes to the next plate--from the lower extremity of which another portion of the fine material escapes in the same manner and so on. The water which passes upwardly through the screen from the first or uppermost plate, af ter acting on the material on top of the screen, again passes downwardly through the screen to the next plate, flows downwardly on said plate and again passes up through the screen to the top thereof, and again down through the screen to the next plate and so on. In this way the water is used over and over again, to act on the top of the screen in the manner just explained, thus obviating the necessity of discharging wash water thereon from above, in order to prevent the material from clogging the screen and maintaining its entire surface active at all times for screening purposes.

Having thus described my invention, what I claim is:

1. The combination with a frame, and sieve material applied thereto, of a number of metal plates rigidly mounted on the frame and having their lower extremities curved respectively upwardly out of the plane of their body portions, to points near the sieve material of the screen, the upper extremity of the lower plates being below the lower extremities of the adjacent upper plates, having an open space left between the lower extremity of one metal plate and the upper extremity of the plate next below it, for the purpose set forth.

2. A screen consisting of a suitable inclined frame work, sieve material applied thereto, and a number of plates suitably mounted on the frame below the sieve material and adapted to conform to the contour of said frame by having their lower ex tremities curved upwardly within a short distance of the sieve material and an open space left between the lower extremity of one metal plate and the upper extremity of the plate next below it for the purpose of allowing part of the material to escape.

In testimony whereof I affix my signature in presence of two witnesses.

RANDALL P. AKINS.

Witnesses DENA NELsoN, A. J. OBRIEN. 

